Top-Front-End (officially View Recognition) gives two of an object's three orthographic views and asks you to choose the missing one from four drawings.
PAT Grind has 1,200 top-front-end questions at three difficulty levels. Each one is checked by an independent solver and comes with a step-by-step explanation.
How the questions work
- Views use third-angle projection: the top view sits above the front view, and the end view (seen from the right) sits to its right.
- Solid lines are edges you can see. Dashed lines are edges hidden behind the object.
- Widths line up between the top and front views, heights between the front and end views, and depth between the top and end views.
Strategy
- Use alignment: every line in the missing view has to line up with a corner or edge in the views you're given.
- Work out the depth of each feature from the view that shows it, then ask what it looks like from the missing direction.
- A slanted surface shows up as a diagonal line in exactly one view and as a rectangle in the others.
- Decide whether each interior line should be solid or dashed by asking whether anything sits in front of it.
Common traps
- The mirror image of the correct view, or the view from the left instead of the right.
- A hidden edge drawn as a solid line, or a visible edge drawn dashed.
- A drawing that is missing one interior line.